Digital time clock for operation in conjunction with mechanical time clock

ABSTRACT

A digital time clock that may be used in conjunction with a mechanical time clock. The digital time clock is placed on or adjacent to an existing mechanical time clock. A radio frequency identification (RFID) tag is associated with each time card that is distributed to employees. As an employee inserts a time card into the mechanical time clock, the digital time clock detects the proximity of the time card and reads the RFID tag. An RFID identifier is stored along with an indication of the time that the identifier was read. The digital time clock may be kept in a low-power standby state until the time card is detected, at which time the digital time clock enters an operational state. The digital time clock may be transported to a location where payroll is to be performed, and data downloaded to a processing device.

TECHNICAL FIELD

This invention relates to time and accounting systems, and moreparticularly, to time clock systems.

BACKGROUND

Mechanical time clocks have been utilized for over one hundred years totrack the time and attendance of employees. While the technology used toimplement mechanical time clocks has improved over the years, in manyrespects the operation of mechanical time clocks remains fundamentallythe same. Each employee is provided a heavy paper card, often referredto as a time card, that is uniquely associated with the employee. Whenthe employee arrives at their place of employ or other facility thatrelies on accurate recording of attendance, the employee inserts theirtime card into a time clock that contains an accurate time base. Theinsertion of the card causes a mechanically-actuated stamp to print timeand date information on the employee's time card. The time cards areperiodically collected by the employer, and the printed time and dateinformation utilized by the employer to determine the time andattendance record of the employee. Such information is typically used bythe employer to appropriately compensate the employee and as a measureof employee performance.

While mechanical time clocks have long been the most common form of timeclock, digital time clocks are becoming increasingly popular. Digitaltime clocks are typically computer-based systems that may be used totrack employee time. Rather than use a paper time card, in a digitaltime clock system the employee will enter an employee number, swipe amagnetic card through a reader, or otherwise use a technique thatuniquely identifies the employee to the system (e.g., biometricidentification). The advantages to the employer of using a digital timeclock system can be significant. For example, the time and attendancedata is already in digital form and can easily be manipulated to produceemployee reports or process payroll. Since paper cards are no longerused, processing errors may be reduced as a result of lost or mishandledcards. Moreover, digital systems may be less prone to breaking down, andcan be easily upgraded to accommodate new functionality.

Even though digital time clocks offer numerous advantages overmechanical time clocks, many employers are still hesitant to switch to adigital system. The reasons for not switching are varied and depend onthe individual employer. For example, some employers may not want toswitch because of the time and expense of replacing their existingmechanical system. Others may be hesitant to switch because they areuncomfortable with new technology and may question the reliability andaccuracy of newer digital systems. Still other employers may be hesitantto switch because the logistics of training employees on how to use anew digital system can be too daunting. Since many of these employerswould benefit from the features of digital time clocks if they couldovercome their hesitation to adopt the technology, it would therefore bebeneficial if there was a transitional or hybrid solution that wouldallow employers to continue to use their existing mechanical time clockswhile at the same time receiving all of the benefits of a digital timeclock system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagram of a digital time clock that may be usedin conjunction with a mechanical time clock.

FIG. 2 is a block diagram of a hardware architecture for the digitaltime clock.

FIGS. 3A and 3B are flow charts of a method for detecting and recordingtime and date information associated with time cards that are brought inproximity to the digital time clock.

FIG. 4 is a representative user interface of a software application thatmay be used to manage data recorded by the digital time clock.

DETAILED DESCRIPTION

A digital time clock that may be used in conjunction with a mechanicaltime clock is disclosed. The digital time clock is a battery powereddevice that may be placed on or adjacent to an existing mechanical timeclock. A radio frequency identification (RFID) tag is associated witheach time card that is distributed to employees. As an employee insertstheir time card into the mechanical time clock to “clock in” or “clockout,” the digital time clock detects the proximity of the time card.Once the time card is detected, the digital time clock reads the RFIDtag to determine the identity of the employee as reflected by the RFIDidentifier. The RFID identifier is stored along with an indication ofthe time that the identifier was read. At or around the time that thedigital time clock is recording the time and attendance of the employee,the mechanical time clock is printing time and date information on thepaper card of the employee. A duplicate time and attendance record isthereby created for the employee, with one record being stored indigital form by the digital time clock system and the other record beingstored in printed form by the mechanical time clock system. Theduplicate records are created automatically and in parallel, withouthaving to provide an interface between the mechanical and the digitaltime clocks.

A card proximity detection circuit is provided in the digital time clockin order to detect when a time card is brought in proximity to thedigital time clock. The digital time clock may be kept in a low-powerstandby state until the time card is detected. The digital time clockmay then be brought to an operational state for a short period in orderto read the RFID tag on the time card. The identity of the employee (asrepresented by the RFID tag identifier) and a time stamp is stored inmemory by the digital time clock. The digital time clock is thenreturned to the standby state until the detection of the next time card.By cycling between a low-power standby state and a normal poweroperational state, the power used by the digital time clock isminimized. Minimizing power use prolongs battery life and extends thelifespan of the digital time clock.

In some embodiments, the digital time clock is attached on or near tothe mechanical time clock in a fashion that allows the digital timeclock to be periodically removed from the location where it isinstalled. Once removed, the digital time clock may be transported to alocation where payroll or other processing is to be performed. Thedigital time clock is connected to a computer or other processing means,and the data stored in the digital time clock downloaded to the computerfor analysis and manipulation. The digital time clock may then bereinstalled at the location of the mechanical time clock. A lock orother security means may be used to ensure that only authorizedrepresentatives are allowed to remove and transport the digital timeclock.

In some embodiments, easy to use software is provided on the computer orother processing system that receives the downloaded time and attendancedata from the digital time clock. In order to help employers manage thetime and attendance data on the computer system, a user interface isprovided that allows the downloaded data to be viewed as if the datawere printed on time cards. These “virtual” time cards that aredisplayed to the employer on the computer monitor ease the transition tousing a digital time clock, as the employer is presented with aninterface (i.e., an electronic version of a time card) that they arealready very comfortable with using.

The following description provides specific details for a thoroughunderstanding of, and enabling description for, various embodiments ofthe technology. One skilled in the art will understand that thetechnology may be practiced without these details. In some instances,well-known structures and functions have not been shown or described indetail to avoid unnecessarily obscuring the description of theembodiments of the technology. It is intended that the terminology usedin the description presented below be interpreted in its broadestreasonable manner, even though it is being used in conjunction with adetailed description of certain embodiments of the technology. Althoughcertain terms may be emphasized below, any terminology intended to beinterpreted in any restricted manner will be overtly and specificallydefined as such in this Detailed Description section.

FIG. 1 is a perspective view of an environment in which a digital timeclock 100 may be used. The digital time clock 100 is attached on,adjacent to, or embedded within a mechanical time clock 105. In FIG. 1,the digital time clock is depicted as being attached on the bottom ofthe mechanical time clock, but in practice the digital time clock may beattached to the top, the back, or the right or left sides of themechanical time clock. The digital time clock may also be attached tothe wall or other support fixture (not shown) to which the mechanicaltime clock is affixed. For example, the digital time clock may belocated on a wall or support fixture above, below, behind, or to eitherside of the mechanical time clock. The digital time clock may also beembedded within the mechanical time clock, such as within the case ofthe mechanical time clock or as a module that is removable from themechanical time clock. As will be appreciated from the discussionherein, the digital time clock 100 merely needs to be in close enoughproximity to the mechanical time clock 105 so that the digital timeclock can detect when a paper or other physical time card 110 is, or isabout to be, inserted into the mechanical time clock 105.

When a time card 110 is inserted by an employee into the mechanical timeclock 105, time and attendance information is printed on the time card110 by the mechanical time clock in a manner well known to those skilledin the art. At or around the time that the mechanical time clock isprinting time and attendance information on the time card, the digitaltime clock reads a radio frequency identification (RFID) tag 115 thathas been placed on the time card. The RFID tag contains an identifierthat associates the time card 110 with an employee. By reading theidentifier from the RFID tag, the digital time clock is thereby able todigitally store time and attendance information associated with thatemployee in a memory contained in the digital time clock. The time andattendance information stored by the digital time clock is created at ornear the same time as the time and attendance information is printed bythe mechanical time clock, and may be considered to be a duplicaterecord of the time and attendance of the employee. The informationstored on the printed time card and the information stored in thedigital memory may be correlated as described below.

Time cards 110 may be purchased by the employer from a supplier with theRFID tags 115 already pre-applied to the cards. Alternatively, theemployer may be able to purchase a quantity of RFID tags and apply thetags to time cards that have been separately acquired. The RFID tags maybe single use (e.g., a sticker that may be applied to a time card) ormultiple use (e.g., a plastic fob that may be temporarily attached to atime card and moved between time cards). In some embodiments, the RFIDtags 115 may be read-only tags, in which case the identifier that isstored in each RFID tag is determined by the manufacturer of the RFIDtags. In some embodiments, the RFID tags may be read/write tags, or tagsfrom which stored data may be read and to which new data may be written.If the RFID tags are read/write tags, the identifier that is stored ineach RFID tag may be determined by the manufacturer of the RFID tags ormay be stored by the employer. The employer maintains a table or otherdatabase that correlates the RFID tag identifier with the employee towhich the time card is distributed. The table or other database may beconstructed before the time cards 110 are distributed to employees, orafter the time cards have been collected from employees. In thisfashion, the employer is able to quickly correlate time and attendanceinformation with the appropriate employee by comparing the identifiersthat are read from the RFID tags with the maintained table or otherdatabase.

On a periodic basis, usually once every pay period, the physical timecards 110 may be collected by the employer and the information on thecards used to process the payroll or other time and attendance function.As those skilled in the art will appreciate, the processing of timecards is largely a manual process to derive the necessary employmentstatistics for each employee. In a similar manner, on a periodic basis,the information that is stored in the digital time clock 100 may bedownloaded and processed in order to determine the employment statisticsfor each employee. In some embodiments, the digital time clock 100 issecured at or near to the mechanical time clock in a fashion that allowsthe digital time clock 100 to be removed and transported to a computer120 or other processing device where the data may be downloaded. Forexample, the digital time clock may be secured by a releasable mount,with screws, with Velcro, or with any other attaching mechanism thatallows the digital time clock to be removed from the location where itis mounted and transported to the processing location. Any of theattaching mechanisms for the digital time clock may include a key orother security feature that prevents the time clock from being removedfrom its mounting location by unauthorized users (i.e., by those thatdon't have lawful access to the key or security code, password, etc.)

When the digital time clock 100 has been removed from its mountinglocation, it may be transported to the computer 120 or other processingdevice where the data may be downloaded from the digital time clock. Aswill be described herein, the digital time clock may be connected to thecomputer via a USB port, Ethernet port, or other communicationinterface. Data within the digital time clock is then downloaded forfurther processing by the computer. For example, the data may be used bythe computer to process the payroll and pay employees, keep track ofused vacation or sick time, etc. Once the data has been downloaded, thememory of the digital time clock is cleared of accumulated and storeddata. The digital time clock may then be returned to its mountinglocation next to the mechanical time clock to continue to recordemployee time and attendance data.

During the period that the digital time clock 100 is not on or near tothe mechanical time clock, those skilled in the art will appreciate thatno time and attendance data will be captured and stored by the digitaltime clock for any employees entering or leaving during this period. Theimpact of such disruption to data collection is minimized by the factthat the mechanical time card system will continue to operate during theperiod that the digital time clock is absent, so the time and attendancedata for employees will still be maintained on the physical time cardsduring the period. The impact of such disruption to data collection mayalso be minimized by scheduling the time when the digital time clock isremoved for those hours when the employee are typically not present(e.g., such as after closing or between shifts). Such disruption mayalso by minimized by maintaining two digital data clocks, and replacingthe first digital time clock with the second digital time clock when thefirst digital time clock is removed, and vice-versa.

In some embodiments, the digital time clock 100 may be connected to thecomputer 120 or other processing device with a wired or wirelessnetwork. When connected to the computer via a wired or wireless network,data from the digital time clock may, on a periodic basis or on acontinuous basis, be transmitted to the computer and stored forprocessing. In such a case, the digital time clock would not need to beremoved from its location adjacent to the mechanical time clock. Thedigital time clock may therefore be mounted in a more secure fashionthan that contemplated by a removable mount.

In some embodiments, a portable reader device (not shown) may be carriedby an employer and connected to the digital time clock 100 using a wiredor wireless connection. The communication connection may be establishedwithout removing the digital time clock from its location adjacent tothe mechanical time clock. Once the connection is established, data maybe downloaded from the digital time clock to the portable reader device.The portable reader device is then transported by the employer andconnected to the computer 120 using a wired or wireless connection. Theportable reader device downloads the time and attendance data from thedigital time clock to the computer 120, where it may be processed aspreviously described.

In response to the collection of time and attendance data, the digitaltime clock 100 may also transmit a wired or wireless trigger signal 125to a remote control device 130. The remote control device may beconnected to actuators, locks, or other control mechanisms to implementa desired function when the wireless trigger signal is received. Forexample, the remote control device 130 may be connected to anelectronically-lockable door that is configured to remain locked untilan employee has appropriately clocked in or clocked out of the timeclock. The digital time clock 100 may therefore send an appropriatetrigger signal to the remote control device when the digital time clockrecords a valid time and attendance record for an employee.

FIG. 2 is a block diagram of a representative hardware architecture forthe digital time clock 100. A central processing unit (CPU) 205 andmemory 210 are coupled by a bus 220. The memory may be non-volatile orvolatile storage such as flash memory, RAM, ROM, magnetic computerstorage devices such as hard disks, or other types of memory. One ormore application programs are stored within the memory and executed bythe CPU and other components in order to implement the functionalitydescribed herein. A counter 215 is coupled to the bus and provides atime base that is used as the basis to record a time and attendanceevent of an employee. In some embodiments, the counter is a 16-bitcounter that increments one count every minute in all operating modes.That is, the counter continues to increment whether the digital timeclock is in a low-power standby mode or in an operational mode asdescribed below. The counter may also continue to increment for a shortperiod even if power to the time clock is interrupted (e.g., whenbatteries contained in the time clock are changed).

Various components are provided to provide status and other informationto an employee using the digital time clock 100 or to an employer thatoperates the digital time clock. A display 235 and/or a speaker 240 arecoupled to the bus 220. The display may comprise one or more LEDs thatindicate to an employee when a time card has been detected and the RFIDtag on the time card read. For example, a green LED may flash when thedigital time clock detects and reads an RFID identifier without error,and a red LED may flash when a time card is detected but a valididentifier is not read. Alternatively or in addition to the LEDs, thedisplay may comprise an LCD or other display panel that provides atextual or graphical display to an employee to indicate the detectionand reading of the time card without error. The same or a differentdisplay may also be used to convey information to the employer. One ormore buttons or switches (not shown) may be included that, whendepressed or selected, allow the employer to check the proper operationof the digital time clock or the status of the time clock. For exampledepressing a particular combination of buttons may instruct the digitaltime clock to indicate the amount of remaining memory space in the timeclock, the number of recorded time and attendance events since theinstallation of the time clock, or any other statistical pieces ofinformation that would be beneficial to the employer.

A radio frequency identification (RFID) circuit 245 is coupled to thebus 220 and to an antenna 255 to enable the digital time clock to readRFID tags. The RFID circuit 245 allows the digital time clock to readidentification numbers from passive RFID tags by transmitting a radiofrequency signal over the antenna and detecting the backscattered signalfrom the tag. If active RFID tags are utilized by an employer, the RFIDcircuit 245 may also be capable of transmitting to and receiving signalsfrom the active tag, and directing the active tag to store one or morepieces of data that is transmitted from the digital time clock.

Several components are provided in the digital time clock 100 to allowthe time clock to communicate with computers or other devices that areexternal to the time clock. A communication circuit 250 that is coupledto the bus 220 and to the antenna 255 may be used in a variety ofcontexts. In some embodiments, the communication circuit is used totransmit data stored in the digital time clock to an external device,such as a computer via a wireless network or to a portable readerdevice. In some embodiments, the communication circuit may be usedtransmit a trigger signal to a remote control device 130. Those skilledin the art will appreciate that one or more antennas may be requireddepending on the particular communication frequencies that are beingutilized. Additionally, a port 260 such as a USB port or an Ethernetport may be coupled to the bus 220. The digital time clock maycommunicate with computers or other devices that are connected via theport 260.

Power is provided to the digital time clock 100 by one or more batteries230. Batteries may be rechargeable batteries or replaceable batteries,or the time clock may be constructed in such a way that the entire timeclock is designed to be replaced when the batteries are depleted. Abattery monitoring and control module 225 is coupled to the batteries tomonitor the overall state of the batteries. In order to maximize batterylongevity, the digital time clock is preferably kept in a low-powerstandby state until a time card 110 is detected in proximity to the timeclock. When a time card is detected, the digital time clock is broughtto an operational state for a short period of time in order to read theRFID tag on the time card. The transition between the low-power standbystate and the operational state may be controlled by the batterymonitoring and control module 225 based on a signal received from a cardproximity detection circuit 265.

A variety of technologies may be used to implement the card proximitydetection circuit 265, depending on the environmental conditions inwhich the digital time clock is to be operated. For example, aphotosensor may be added to the time clock and oriented in such a waythat the photosensor will be shielded from ambient light when a timecard is being inserted into the mechanical time clock. When a drop inlight is detected, the card proximity detection circuit 265 may assumethat a time card is being inserted and send a signal to the batterymonitoring and control module 225 to cause the digital time clock toreturn to the operational state. As another example, a small light orsound transponder may be provided to transmit a signal and detect anecho of light or sound waves from a time card. As still another example,a mechanical switch may be provided and oriented in such a way that theinsertion of a time card into the mechanical time clock will trigger theoperation of the switch. As yet another example, an inductive sensor maybe provided that detects the motion of actuators or the operation ofother components within the mechanical time clock. Any technology may beused that enables the card proximity detection circuit 265 to detect theproximity of the time card in a reliable fashion. The handling of errorsin detecting the proximity of a time card are discussed in greaterdetail with respect to FIGS. 3A-3B below.

Those skilled in the art will appreciate that the card proximitydetection circuit 265 may be omitted if battery life is not a concern orif the trade off in cost or performance is insufficient to justifyswitching between a standby state and an operational state. For example,it may be possible to utilize components that operate at a sufficientlylow power to enable the operational lifespan of the digital time clockto be extended without having to rely on entering a standby state.Alternatively, the inherent operation of the time clock may cause thebatteries to be charged on a frequent basis (e.g., such as when coupledto a computer to allow downloading of data from the time clock), therebyminimizing the importance of power management.

FIGS. 3A and 3B are flow charts of a process 300 for reading an RFID tagand storing the read data for subsequent processing. At a decision block305, the digital time clock detects that a time card is in closeproximity to the time clock. As was previously described with respect tothe card proximity detection circuit 265, various technologies may beused to detect the presence of a time card. If a time card is detected,processing continues to a block 310 where a pulse counter is set tozero. The pulse counter is used to track the number of attempts that aremade to read an RFID tag. Because of the nature of the operatingenvironment, the card proximity detection circuit 265 may periodicallyreport false detection events. For example, the detection circuit mayincorrectly believe that a time card is present if an employee brushesup against the digital time clock. As another example, the detectioncircuit may correctly detect the presence of a time card, but anemployee may drop the time card before it can be read or inserted intothe mechanical time clock system. Rather than continuously attempting todetect the RFID tag and depleting the batteries, the digital time clocktherefore makes a fixed number of attempts to read the RFID tag. If theRFID tag is not read by the time that the fixed number of attempts iscomplete, it is presumed that the original signal from the cardproximity detection circuit was generated in error or that the profferedtime card does not have the correct type of RFID tag.

At a block 315, the RFID circuit 245 pulses the antenna 255 to send asignal that will induce a response from an RFID tag 115. At a block 320,the RFID circuit attempts to detect the response from the RFID tag. Inthis particular application, the response typically includes a uniqueidentifier that associates the time card with a particular employee.Additional information, however, may also be encoded in the RFID tag,such as a particular group or division that the employee is associatedwith. At block 320, the pulse count is also incremented to indicate thatan initial read attempt has been made to detect the RFID tag.

At a decision block 325, the digital time clock determines whether theread of the RFID tag was successful. A read is successful if a uniqueidentifier having a desired format is read from the RFID tag. (In someembodiments, it may be necessary for two or more reads to detect thesame unique identifier for the digital time clock to judge that the readhas been successful.) If the read was not successful, at a decisionblock 330, a test is made by the digital time clock to determine whetherthe pulse count has exceeded the threshold number of read attempts thathave been determined to be sufficient for the operating environment. Forexample, in certain environments the threshold may be set at threeattempts, and the digital time clock will cease read attempts if threepulses have been emitted without successfully reading the RFID tag. Inother environments, the threshold may be set at five attempts, and thedigital time clock will cease read attempts if five pulses have beenemitted without successfully reading the RFID tag. If the pulse counthas exceeded the set threshold without a successful read, the processreturns to decision block 305 where the digital time clock waits todetect the next time card. If the pulse count has not exceeded the setthreshold, processing continues to block 335 where a delay betweenpulses is introduced. Such a delay may vary depending on the anticipatedspeed that an employee will move the time card, but typically is 0.5seconds or less. After the delay, another pulse is made on the antennaat block 315 and another attempt is made to read the RFID tag.

If the RFID tag is successfully read, at a decision block 340 a test ismade by the digital time clock to determine whether the same time cardhas been read twice in close succession. Such an error may occur, forexample, if an employee leaves their time card in or near the mechanicaltime clock for a longer than normal period. To test for the duplicatereading of the same time card, a test is performed at decision block 340to determine whether (i) the identifier read from the RFID tag is thesame identifier that was previously read, and (ii) less than two minuteshave elapsed. The reading of the same identifier from a time card twicein such short succession is presumed to be in error. If the sameidentifier was read twice within the last two minutes, at a block 345the data pertaining to the second reading of the identifier isdiscarded. Processing then continues at decision block 305 where thedigital time clock waits to detect the next time card.

If the same identifier was not read twice in the last two minutes,processing continues to block 350. At block 350, the digital time clockstores the RFID tag identifier in memory 210 along with the value of thecounter 215. As was described above, the counter is a time thatincrements once each minute regardless of whether the digital time clockis in a standby state or in an operational state. The value of thecounter that is stored is therefore reflective of the time that the timecard was inserted into the mechanical time clock. The process ofsubsequently reconciling the value of the counter with the timemaintained by the mechanical time clock will be described with respectto FIG. 4.

At decision block 355, a test is made by the digital time clock todetermine whether the RFID tag is a read/write tag. Such a determinationcan typically be made by decoding information that is read from the RFIDtag. If the RFID tag is a read/write tag, at a block 360 the value ofthe counter 215 is transmitted to the RFID tag for storage in the tag.By storing the counter value in the RFID tag, two records of theemployee's time and attendance events are maintained by the time card.The first record is the information mechanically printed on the timecard by the mechanical time clock. The second record is the informationdigitally stored in the RFID tag by the digital time clock.

At a block 365, a trigger signal is optionally transmitted by thedigital time clock to a remote control device 130. As was previouslydiscussed, such a trigger signal may cause a door to be unlocked, acamera to be enabled, or any other process to be initiated that anemployer may want to be tied to the clocking in or clocking out of anemployee.

At a block 370, the display 235 and/or speaker 240 are controlled by thedigital time clock to indicate a successful event, e.g., the detectionand reading of an RFID tag. Various audible and visual cues may be givento employees depending on the desired amount of instruction. Once anRFID tag has been successfully read, stored, and messaged, processingcontinues to decision block 305 where the digital time clock waits todetect the next time card.

On a periodic basis, the information that is stored in the digital timeclock 100 may be downloaded and processed in order to calculate thenecessary payroll and employment statistics for each employee. As waspreviously described, various methods may be used to transfer data fromthe digital time clock to a computer, such as physical transport andconnection to the computer, wired or wireless network transfer to thecomputer, or the user of a portable reader device. Once the data hasbeen transferred to a computer or other processing device, variousinterfaces may be provided to the employer to allow the employer tomanipulate the data. FIG. 4 is an example of a representative userinterface 400 for an application, such as a payroll processingapplication, that may be used by an employer to view and/or manipulatethe data downloaded from the digital time clock. Although the interfaceis indicated as being accessed using a dedicated software application,the interface may also be incorporated in a standard browserapplication, such as Internet Explorer or Firefox.

The user interface 400 is divided into a number of regions forpresentation of data to the employer. In the first region, the time andattendance data is displayed to the user in the form of a “virtual” timecard 410. That is, a graphical display of a time card is displayed tothe employer, with time and attendance data that was downloaded from thedigital time clock displayed on the time card as if it had beenimprinted on the time card by a mechanical time clock. The employer maybe given an option of selecting a desired format of time card thatmatches a format of the time card that is used by the employer. Thedisplay of the virtual time card 410 will then be changed to match thephysical time card of the employer. Displaying the data on a virtualtime card serves a number of purposes. For example, employers that arenot very familiar with computers or computer applications are presentedwith a visual interface that they can readily understand based on theirprior experience with mechanical time clocks. Employers are also able tomore readily compare the virtual time card 410 with the correspondingmechanically-stamped time card 110 that is also in the employer'spossession. Displaying virtual time cards therefore makes it much easierfor employers to ultimately transition from a mechanical time cardsystem to a digital time card system.

In a second region 415 of the user interface, the employer is presentedwith stored information about the employee, including the employee'sname, address, phone number, and various other details. In particular, aRFID identifier field 420 is provided to allow the employer to input theidentifier of the RFID tag that was placed on the employee's time card.By entering the identifier, a correlation is made between the employee'sinformation and the particular time card that the employee is using.Alternatively, an RFID tag identifier may be automatically assigned byan application used by the employer without requiring the employer tomanually enter the identifier. For example, a scanning system may beprovided that allows each of the time cards to be scanned or read andthe identifier on the RFID tag correlated with the identity of theemployee. As another example, each time card may be printed with anumber that is correlated with the RFID tag identifier associated withthat time card. In such circumstances, the employer would enter the timecard number for an employee, and the application would automaticallyassociate the RFID tag identifier with that employee based on a look-uptable provided by the time card manufacturer. When an RFID identifier isautomatically assigned using these or similar techniques, it may not benecessary to display the actual RFID identifier in identifier field 420.

In a third region 425 of the user interface, the employer is presentedwith various payroll statistics of the employee, such as total hoursworked to date, aggregate amount paid, etc. The amount of statistics andthe period over which the statistics are computed may be selected by theemployer.

In order to reconcile the counter values that are stored in the memoryof the digital time clock with the time values that are mechanicallyrecorded on the time card, a fourth region 430 may be provided on theuser interface for one or more employees. In the fourth region, theemployer is asked to manually enter information that is contained on theemployee's time card 110. In a field 435, the employer is asked to enterthe first clock-in time on the employee's time card. In a field 440, theemployer is asked to enter the last clock-out time on the employee'stime card. When the payroll processing application receives manuallyentered values for the first clock-in time and the last clock-out time,it can correlate those actual clock times with the stored counter valuesthat are associated with the first clock-in and the last clock-out asrecorded by the digital time clock. Since the counter is consistentlyincremented in 1-minute increments, all other values of the counter maybe then be translated into the appropriate time and date by the system.Those skilled in the art will appreciate that the questions in thefourth region need only be answered by the employer for a singleemployee in any pay period, as once correlated, the correlation may beused by the payroll application for all other employee data that wasrecorded during that period.

In some embodiments, the fourth region may be presented to the employeron a periodic basis, such as in the first screen that the employer seesupon entering the application to process payroll or once for eachcalendar week for which the application receives data. By requiring theemployer to confirm one or more clock-in or clock-out times for one ormore employees on a periodic basis, the application is able to maintaina desired degree of accuracy between the time represented by the counterand the time reflected by the mechanical time clock.

In some embodiments, the fourth region may be omitted in its entirelyand the correlation determined based on a local clock that is maintainedby the computer running the payroll processing application. When theinformation stored in the digital time clock 100 is downloaded to acomputer for processing, a counter value reflective of the time atdownload may be transferred from the digital time clock in addition tothe time and attendance data. By comparing the received counter valuewith the value of a local clock maintained by the computer, an initialcorrelation of counter value to mechanical time clock value may be made.The employer may be presented with employee time and attendance databased on this initial correlation, and allowed to refine the correlationto account for any difference between the time maintained by thecomputer and the time maintained by the mechanical time clock.

It will be appreciated that the disclosed digital time clock allowsemployers to continue to use their existing mechanical time clocks whileat the same time receiving all of the benefits of a digital time clocksystem. Such a time clock is therefore particularly beneficial to thoseemployers that are interested in slowly transitioning to a digitalsystem, but may initially be skeptical of the technology.

The above detailed description of embodiments of the system is notintended to be exhaustive or to limit the system to the precise formdisclosed above. While specific embodiments of, and examples for, thesystem are described above for illustrative purposes, various equivalentmodifications are possible within the scope of the system, as thoseskilled in the relevant art will recognize. For example, while RFIDtechnologies are discussed herein, the disclosed system and method isequally applicable to any wireless technology that allows an identifierto be read remotely. As another example, while processes or blocks arepresented in a given order, alternative embodiments may perform routineshaving steps, or employ systems having blocks, in a different order, andsome processes or blocks may be deleted, moved, added, subdivided,combined, and/or modified to provide alternative or subcombinations.Each of these processes or blocks may be implemented in a variety ofdifferent ways. Also, while processes or blocks are at times shown asbeing performed in series, these processes or blocks may instead beperformed in parallel, or may be performed at different times.

The teachings of the methods and system provided herein can be appliedto other systems, not necessarily the system described above. Theelements and operation of the various embodiments described above can becombined to provide further embodiments. For example, while thedisclosed technology may be favorably used to improve the performance ofdigital time clocks, those skilled in the art will appreciate that thetechnology is equally applicable to any RFID reading device that wouldbenefit from low-power operation. The card proximity detection circuit265 may be adapted to detect any tangible item that is brought intoproximity with the reading device. Once a tangible item is detected, thereading device may be brought from a low-power quiescent state to anoperational state for a short period of time in order to attempt to readan RFID tag on the tangible item. After an RFID tag has been read or atimeout period has elapsed, the reading device may be returned to thelow-power quiescent state until the next tangible item is detected. Bycycling to an operational state only when a tangible item is detected,the power consumption of the reading device is reduced. Such technologyis therefore particularly applicable for battery-operated RFID tagreaders.

As another example, with little modification the disclosed digital timeclock may also be used to read time cards that carry identificationinformation in a manner other than RFID tags. For example, instead ofutilizing RFID tags, time cards 110 may be imprinted with bar codes thatreflect a unique identifier. In such an environment, the RFID circuit245 may be replaced with a bar code reader (not shown) that is able toscan and read bar codes in proximity to the digital time clock. As atime card imprinted with a bar code is inserted into the mechanical timeclock, the time card would be detected and the bar code reader wouldread the code from the time card. The digital time clock may be cycledfrom a quiescent state to an operational state to save power duringperiods in which a time card is not detected.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof, means any connection or coupling,either direct or indirect, between two or more elements; the coupling ofconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, shall referto this application as a whole and not to any particular portions ofthis application. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or,” in reference to alist of two or more items, covers all of the following interpretationsof the word: any of the items in the list, all of the items in the list,and any combination of the items in the list.

While certain aspects of the technology are presented below in certainclaim forms, the inventors contemplate the various aspects of thetechnology in any number of claim forms. For example, while only oneaspect of the invention is recited as embodied in a computer-readablemedium, other aspects may likewise be embodied in a computer-readablemedium. Accordingly, the inventors reserve the right to add additionalclaims after filing the application to pursue such additional claimforms for other aspects of the technology.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

1-54. (canceled)
 55. A digital time clock for operation in conjunctionwith a mechanical time clock, the digital time clock comprising: a powersupply for supplying power to the digital time clock; a time base forgenerating an indication of time; a storage area for storing data; acard detection component for detecting the presence of a time card neara mechanical time clock, wherein the digital time clock is cycled from aquiescent state that draws low power from the power supply to anoperational state when the time card is detected; and a bar code readerthat, when the digital time clock is in the operational state, reads anidentifier from a bar code that is associated with the time card andstores the identifier and a time from the time base reflecting thedetection of the time card in the storage area.
 56. The digital timeclock of claim 55, wherein the power supply is a battery.
 57. Thedigital time clock of claim 55, wherein the time base is a counter thatis incremented at fixed intervals.
 58. The digital time clock of claim55, wherein the time base is a clock.
 59. The digital time clock ofclaim 55, wherein the card detection component is a photosensor.
 60. Thedigital time clock of claim 55, wherein the card detection component isa transponder that emits a signal and detects a reflected echo signalfrom the time card.
 61. The digital time clock of claim 55, wherein thecard detection component is a switch that is triggered by the insertionof the time card into the mechanical time clock.
 62. The digital timeclock of claim 55, wherein the card detection component is an inductivesensor that detects the operation of the mechanical time clock.
 63. Thedigital time clock of claim 55, wherein the bar code is imprinted on thetime card.
 64. The digital time clock of claim 55, further comprising amounting component to secure the digital time clock to the mechanicaltime clock.
 65. The digital time clock of claim 64, wherein the mountingcomponent includes a locking mechanism to prevent the digital time clockfrom being removed from the mechanical time clock without acorresponding unlocking mechanism.
 66. The digital time clock of claim55, wherein the digital time clock is incorporated in a housing of themechanical time clock.
 67. The digital time clock of claim 55, furthercomprising a port that is coupled to the storage area and which iscoupleable to a computer so that data stored in the digital time clockmay be downloaded to the computer.
 68. The digital time clock of claim55, further comprising a wireless transmitter coupled to the storagearea so that data stored in the digital time clock may be wirelesslytransmitted to a computer.
 69. The digital time clock of claim 55,further comprising a network transmitter coupled to the storage area sothat data stored in the digital time clock may be transmitted to acomputer via a network.
 70. A digital time clock for operation inconjunction with a mechanical time clock, the digital time clockcomprising: a time base for generating an indication of time; a bar codereader that, when the digital time clock is in proximity to a mechanicaltime clock, reads an identifier from a bar code that is associated witha time card being inserted into the mechanical time clock; and acommunications component that communicates to a remote computer, foreach time card that is inserted into the mechanical time clock, theidentifier and a time from the time base reflecting the insertion of thetime card into the mechanical time clock.
 71. The digital time clock ofclaim 70, further comprising a power supply for supplying power to thedigital time clock.
 72. The digital time clock of claim 71, wherein thepower supply is a battery.
 73. The digital time clock of claim 70,wherein the time base is a counter that is incremented at fixedintervals.
 74. The digital time clock of claim 70, wherein the time baseis a clock.
 75. The digital time clock of claim 70, further comprising acard detection component for detecting the presence of a time card nearthe mechanical time clock, the card detection component causing the barcode reader to read a bar code that is associated with the time cardwhen the presence of the time card is detected.
 76. The digital timeclock of claim 75, wherein the card detection component is aphotosensor.
 77. The digital time clock of claim 75, wherein the carddetection component is a transponder that emits a signal and detects areflected echo signal from the time card.
 78. The digital time clock ofclaim 75, wherein the card detection component is a switch that istriggered by the insertion of the time card into the mechanical timeclock.
 79. The digital time clock of claim 75, wherein the carddetection component is an inductive sensor that detects the operation ofthe mechanical time clock.
 80. The digital time clock of claim 70,wherein the bar code is imprinted on a time card.
 81. The digital timeclock of claim 70, further comprising a mounting component to secure thedigital time clock to the mechanical time clock.
 82. The digital timeclock of claim 81, wherein the mounting component includes a lockingmechanism to prevent the digital time clock from being removed from themechanical time clock without a corresponding unlocking mechanism. 83.The digital time clock of claim 70, wherein the digital time clock isincorporated in a housing of the mechanical time clock.
 84. The digitaltime clock of claim 70, wherein the communications component comprises:a storage area for storing, for each time card, data comprising theidentifier and the time from the time base reflecting the insertion ofeach time card into the mechanical time clock; and a port that iscoupled to the storage area and which is coupleable to the remotecomputer so that data stored in the digital time clock may be downloadedto the remote computer when the digital time clock is transported to theremote computer.
 85. The digital time clock of claim 70, wherein thecommunications component comprises a wireless transmitter for wirelesslytransmitting, for each time card, the identifier and the time from thetime base reflecting the insertion of the time card into the mechanicaltime clock to the remote computer.
 86. The digital time clock of claim70, wherein the communications component comprises a transmitter coupledto a wired network for transmitting, for each time card, the identifierand the time from the time base reflecting the insertion of the timecard into the mechanical time clock to the remote computer.
 87. Adigital time clock for operation in conjunction with a mechanical timeclock, the digital time clock comprising: a time base for generating anindication of time; a reader component that, when the digital time clockis in proximity to a mechanical time clock, reads an identifier that isassociated with a time card being inserted into the mechanical timeclock; a communications component that communicates to a remotecomputer, for each time card that is inserted into the mechanical timeclock, the identifier and a time from the time base reflecting theinsertion of the time card into the mechanical time clock; and a triggergeneration circuit that, after the remote reader reads an identifierthat is associated with a time card being inserted into the mechanicaltime clock, transmits a trigger signal to a remote device.
 88. Thedigital time clock of claim 87, wherein the remote device is a computingdevice and the trigger signal causes the initiation of a process that isassociated with the clocking in or clocking out of an employee.
 89. Thedigital time clock of claim 87, wherein the remote device is a door lockand the trigger signal causes a door to unlock.
 90. The digital timeclock of claim 87, wherein the remote device is a door lock and thetrigger signal causes a door to lock.
 91. The digital time clock ofclaim 87, wherein the remote device is a camera and the trigger signalcauses the camera to be enabled.
 92. A digital time clock for operationin conjunction with a mechanical time clock, the digital time clockcomprising: a time base for generating an indication of time; a radiofrequency identification tag reader that, when the digital time clock isin proximity to a mechanical time clock, reads an identifier from aradio frequency identification tag that is associated with a time cardbeing inserted into the mechanical time clock; a communicationscomponent that communicates to a remote computer, for each time cardthat is inserted into the mechanical time clock, the identifier and atime from the time base reflecting the insertion of the time card intothe mechanical time clock; and a radio frequency identification tagwriter that, when the radio frequency identification tag is a read/writeradio frequency identification tag, directs the read/write radiofrequency identification tag to store data.
 93. The digital time clockof claim 92, wherein the stored data comprises a representation of atime from the time base reflecting the insertion of the time card intothe mechanical time clock.